I am about to check my valves on my 2002 raptor for the first time. I know I have to take all the plastic off the front and everything, and pretty much know what i am doing but have a few quick quewstions, Do I line up the timing mark at top dead center on the compression stroke and then check all 5 valves or is there a certain way that it has to be done, that is my guess, but if I am wrong then I need to know the proper proceedure. Anything else i should look at while checking and adjusting the valves??

 

Pull the spark plug, remove both plugs on the left side case, put a socket on the crank nut, put finger in spark plug hole & turn crank nut counterclockwise until you feel compression from the spark plug hole, line up timing marks. You are now at TDC & can adjust all 5 valves. I've adjusted mine 3 times so far & only the intakes needed adjusting, the exausts haven't needed it yet.

While you've got that much apart it would be a good time to match port your intake maifolds. Mine were off bt 1/16" & that causes extra turbulance in the intake tract.

It's also a good time to check all bolts & wiring you can't normaly get to.

 

match port? uhm, can u please shed some info on this for the people that are that up to speed on this subject?
thanks.




<< While you've got that much apart it would be a good time to match port your intake maifolds. Mine were off bt 1/16&quot; &amp; that causes extra turbulance in the intake tract. >>

 

The holes in the intake manifolds don't always line up with the intake holes in the head, take off your carbs &amp; run your finger in the manifold, you'll feel the ridge between the head &amp; manifold This causes turbulance in the intake. Smoothing these edges to match smoothes the air flow &amp; can improve your Raptors breathing.

Do a search on match porting. There was somthing about that in the last couple of weeks.

 

thanks Moose your info is greatly appreciated. i aways read what you have to say in your posts, you sound very knowledgeable. i did the search and read up and it sounds like only racers would do such a thing to gain a sec or two? doesn't sound like it worth the trouble?

 

It doesn't take much more time than puting on a pipe &amp; rejetting, &amp; improving the air flow means more power. I've been doing it on VW's for years.

But you are right I'm hoping to gain a tenth of a second at the drags! It's not much but a tenth here &amp; there adds up. I'm just tring to maximize my engines output without going into the motor. I'll use all the little tricks I can find!

 

Thanks for all the help, I adjusted them, only the intake valves were off!! they had almost 0 clearance..but it is all better now! how often would you say that they need checked? I had about 20-25 hours on it and they were due. thanks again for your great help!

 

I adjust my valves every 20 hours.